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The TDI-Dynaload RBL488 Series is a family of single-channel programmable DC electronic loads designed for testing power supplies, fuel cells, large batteries, and other DC power equipment. Each unit operates as a precision instrument that simulates DC loads to test power supplies, generators, servo systems, batteries, and similar DC sources. The series covers ratings up to 1000 Amps with chassis sizes from a compact 400-watt half-rack unit through a 4000-watt full-rack 19-inch configuration.
Applications for the RBL488 Series include power supply transient response testing, battery testing and analysis, fuel cell characterization, and general DC source verification. The high range current capability and constant power feature facilitate battery testing and analysis, while the ultra-fast slew rate provides power supply transient testing capabilities. The ultra-low voltage, high current capability — operation below 0.5 volts at 1000 Amps — makes the series suitable for fuel cell requirements where source compliance is limited.
ValueTronics stocks and supplies the TDI-Dynaload RBL488 Series from our 20,000 sq ft secure warehouse at 1675 Cambridge Drive in Elgin, Illinois, where instruments are inventoried, inspected, and tested before they ship. Operating since 1992, ValueTronics is a direct, accountable source for test and measurement equipment — not a drop-shipper or pass-through broker. Every RBL488 unit that leaves our facility has been handled by our team, with condition documentation and warranty terms backed by ValueTronics directly.
Transistor Devices, Inc. (TDI) acquired the Dynaload electronic load product line and has operated it as the TDI-Dynaload Division, headquartered in Hackettstown, New Jersey. The Dynaload name itself dates to earlier electronic load product generations and remains a registered trademark of Transistor Devices, Inc.
The RBL488 Series spans four chassis sizes — 400W, 800W, 2000W, and 4000W — across multiple voltage and current rating combinations. Voltage ratings in the family include 50V, 100V, 400V, and 600V options (with a 1000V variant noted as available on RBL 1000V configurations), and current ratings reach as high as 1000 Amps in the highest-power chassis. Each model in the series provides the same five operating modes, the same programming interfaces, and the same protection feature set; the differences across models are physical size, maximum voltage, maximum current, and maximum power dissipation.
Model numbers in the series follow the convention RBL488-[voltage]-[current]-[power], where the three numbers identify the maximum input voltage, maximum input current, and maximum power dissipation respectively. For example, the RBL488 100-120-800 indicates a 100V, 120A, 800W unit, while the RBL488 50-1000-4000 indicates a 50V, 1000A, 4000W unit. This naming convention makes it straightforward to identify the operating envelope of a given model directly from its part number.
Each pre-owned RBL488 Series model below links to its own product page with condition-matched pricing and availability. Configuration, accessories, and documentation specifics are confirmed on each individual model's page.
Within the RBL488 Series, the primary differences between models are the maximum input voltage envelope, the maximum input current capacity, and the maximum power dissipation rating. The 400W chassis is the most compact (8 inches wide x 5.25 inches high x 13 inches deep), while the 4000W chassis occupies a full 19-inch rack at 8.75 inches high and 22 inches deep. The 800W and 2000W chassis fall in between in both physical size and power capability. Variable-speed fans are noted as standard on the 2000W and 4000W models to reduce acoustic noise during bench operation.
Selection between models depends on the source under test: maximum source voltage drives the voltage rating selection, peak load current drives the current rating selection, and steady-state dissipation drives the power rating selection. Because the constant-power mode is independent of voltage and current range, the power rating defines the sustained loading envelope regardless of where in the V/I plane the operating point lies. The comparison table that follows summarizes the key ratings across the available RBL488 Series configurations.
| Model | Max Voltage | Max Current | Max Power |
|---|---|---|---|
| RBL488-400-600-4000 | 400 V | 600 A | 4000 W |
| RBL488-50-150-800 | 50 V | 150 A | 800 W |
| RBL488-100-120-800 | 100 V | 120 A | 800 W |
| RBL488-400-120-800 | 400 V | 120 A | 800 W |
Additional differences in specifications beyond the few shown above are not listed here — see each model's full specifications below.
| Specification | Value |
|---|---|
| Voltage Ranges (Full Scale) | 20 V, 200 V, 400 V |
| Current Ranges (Full Scale) | 20 A, 200 A, 600 A |
| Power | 4000 Watts |
| Short Circuit Resistance | 0.008 Ohms max. |
| Constant Resistance (High Ohms Mode, 20V) | 0 - 0.5 A/V, 0 - 5 A/V, 0 - 15 A/V |
| Constant Resistance (High Ohms Mode, 200V) | 0 - 0.05 A/V, 0 - 0.5 A/V, 0 - 1.5 A/V |
| Constant Resistance (High Ohms Mode, 400V) | 0 - 0.025 A/V, 0 - 0.25 A/V, 0 - 0.75 A/V |
| Constant Resistance (Low Ohms Mode, 20V) | 0 - 5 A/V, 0 - 50 A/V, 0 - 150 A/V |
| Constant Resistance (Low Ohms Mode, 200V) | 0 - 0.5 A/V, 0 - 5 A/V, 0 - 15 A/V |
| Constant Resistance (Low Ohms Mode, 400V) | 0 - 0.25 A/V, 0 - 2.5 A/V, 0 - 7.5 A/V |
| Powermeter Resolution | 1 Watt |
| Size | 19" W x 8.75" H x 22" D (483mm W x 222mm H x 589mm D), Rack Mountable |
| Weight | 85 lbs. / 39 kg |
Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.
Model No
TDI-Dynaload
Condition
Used
Volts
400 V
Amps
600 A
Type
Single
Power
4 kW
Manufacturer
Dynaload
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